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Hello, I'm using the latest java Decoders package and am running into an error trying to decode some GRIB (v1) files. The error occurs when I try to grab data that has a format of simple flags like (0 or 1) or (0,1,2,or 3). What seems to be happening is that the code mistakenly thinks the offset passed in is the Grid Description Section (GDS) even though the data offset is what is being passed in. Normally this is handled ok by the code but when the length of the Binary Data Section(BDS) is small, it mistakenly thinks its in a GDS and subsequently the file pointer gets messed up. In our case, we have a flag parameter that happens to have a very small BDS (its an icing flag and I there was no icing in our area) and hence the length octet is small (12) and therefore less than 50 which fools the code into thinking its in a GDS. This less than 50 check happens around line 129 of the Grib1Data class. My question to the mailing list is whether this is a bug or is there a way I'm misunderstanding the API? I can currently work around this by deliberately bypassing the Grib1Data class. To do so, you just need to do the following: 1) Set the raf (file pointer) to the data offset of your GDS 2) If the Product Data Section (PDS) says that the bms exists, then build a Grib1BitMapSection from the raf. 3) Build a new Grib1BinaryDataSection object from the raf, the decimal scale of the PDS and the above mentioned bms 4) Then call getValues on that object. Does anyone see a problem with my workaround? If it is a bug, it might be easily taken care of by having another Boolean variable passed in that tells the code whether it's a data offset or a gds offset. Any help or comments would be greatly appreciated. Thanks, Sincerely, Mike Macaulay Sr. Software Engineer Lockheed Martin
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